Fuel injection pump



April 26, 1966 v. D. ROOSA FUEL INJECTION PUMP 5 Sheets-Sheet 1 Filed Oct. 23, 1963 Q INVENTOR.

VERNON D. ROOSA BYW WW ATTORNEYS April 26, 1966 v. D. ROOSA 3,247,805

FUEL INJECTION PUMP Filed Oct. 25, 1963 5 Sheets-Sheet 2 r A W W 4lliii ii fii:;ggiiiiiii Ali INVENTOR. 70 VERNON D. ROOSA F/G. 4 W W ATTOR NEYS April 26, 1966 v, oos 3,247,805

INVENTOR. VERNON D. ROOSA BYW ATTORNEYS of the cap and housing.

United States Patent 3,247,805 FUEL INJECTION PUMP Vernon D. lRoosa, West Hartford, Conn. Hartford Machine Screw $0., R0. Box 1440, Hartford, Qonn.) Filed Oct. 23, 1963, tier. No. 318,255 8 (Ilaims. (Ql. 103-161) This invention relates to fuel injection pumps and more particularly to fuel injection pumps of the type having a rotor with plungers reciprocable therein for delivering fuel charges to an associated engine and which are inwardly actuated by an annular cam encircling the rotor.

It is a principal aim of the present invention to provide a new and useful fuel injection pump of the type described which is adapted for being driven at one-half the usual pump speed whereby fuel pump wear is substantially diminished and pump reliability and responsiveness is substantially increased.

It is another aim of the present invention to provide a new and improved fuel injection pump having a compact and sturdy construction with an economical and functionally reliable assembly of parts.

It is a further aim of the present invention to provide a new and useful fuel injection pump which is equally useful for delivering fuel to the cylinders of an in-line engine or a V-type engine.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth, and the scope of the application of which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a longitudinal section view, partly broken away, of a preferred embodiment of a fuel injection pump of the present invention;

FIG. 2 is a transverse section view, partly broken away, taken substantially along line 2-2 of FIG. 1;

FIG. 3 is an enlarged end view of a rotor of the fuel injection pump of FIG. 1;

FIG. 4 isa reduced partial section view taken along line 4-4 of FIG. 3;

FIG. 5 is a reduced partial section view taken along line 5-5 of FIG. 3;

FIG. 6 is a partial transverse section view taken sub' stantially along line 6-6 of FIG. 1;

FIG. 7 is a partial transverse section view taken substantially along line 7-7 of FIG. 1; and

FIG. 8 is a partial transverse section view taken substantially along line 8-8 of FIG. 1.

Referring now to the drawings in detail, a pump 10 exemplifying the present invention is of the type conventionally employed in fuel injection systems for supplying measured fuel charges to an associated internal combustion engine. The pump generally includes a cylindrical casing or housing 12 having an axially extending opening with a bore 14 rotatably supporting a shaft 16. The axial opening 'is enlarged at 13, at the left longitudinal end of the housing as viewed in FIG. 1, for receiving a vane-type fuel transfer pump, generally denoted by the numeral 20, which is connected for being driven by the shaft 16. The housing is threaded at 22 for receiving a transfer pump cap 23 and is recessed for receiving an O-ring 24 provided for preventing leakage through the threaded connection In the usual manner, the transfer pump receives fuel from a pump inlet passage 26 which is threaded for connection to an inlet fuel line, and delivers fuel under pressure to an outlet passage 28 in communication with a bore 30 in which a pump metering valve 32 is mounted. A threaded bore 34 in the housing is provided for connecting the transfer pump outlet passage 28 with a pressure regulator (not shown) which in the usual manner is adapted to regulate the output pres sure of the transfer pump and return excess fuel to the pump inlet 26. Conventionally, the pressure regulator is designed to provide a transfer pump outlet pressure which increases with rotor speed.

A fuel charge pump, generally denoted by the numeral 36, includes a carrier sleeve 37 which is fixed for rotation with the shaft 16 to form with the shaft a pump rotor. The rotor is driven by a pump drive shaft 38through a spline connection between the shaft 38 and an axial extension 40 of the sleeve 37. The drive shaft 38 is suit ably mounted, as by a ball bearing assembly 46, for rotation within a pump mounting bracket 42 fixed to the pump housing by machine fasteners 44. The ball bearing assembly 46 is retained within the bracket 42 by a snap ring 48, and an annular seal 50 and an O-ring 52 are retained by the bracket to prevent fuel leakage from the pump.

In accordance with the present invention, the sleeve 37 of the charge pump 36 has, in the same radial plane, four radial bores 54, shown to be of equal diameter and angularly spaced degrees apart, to provide two pairs of diametrically opposed bores in the pump rotor. Suitable identical plungers 56 are mounted in the bores 54 for reciprocable movement and are adapted to be actuated inwardly during rotation of the rotor by an annular cam ring 58 mounted in an enlarged annular recess 60 of the pump housing. The cam ring 58 has inwardly projecting cam lobes 62 (FIG. 2) for displacing the plungers 56 inwardly, and suitable cam followers 64 and follower shoes 66 are slideably mounted in radial slots 68 in the carrier sleeve 37 intermediate the plungers 56 and the cam ring for translating the cam contour into reciprocable movement of the plungers.

A pair of axially spaced, generally radially extending transverse passages 70, 72 in the shaft 16 communicate respectively with the pairs of opposed bores 54 and thereby provide fuel outlet passages for the charge pump. These transverse passages 70, 72 are placed in communication with a second pair of axially spaced generally radially extending transverse distributor passages 74, 76, respectively, by a pair of axially extending diagonal passages 7-8, 80, respectively. The distributor passages 74, 76 are in turn adapted for registry, respectively, with a pair of axial-1y spaced banks of angularly spaced outtlet passages 82, 84 which are suitably connected with the fuel nozzles of the associated engine, for which purpose the pump housing has a plurality of threaded bores 86 for fuel line connectors (not shown).

Fuel is delivered to the bores 54 of the charge pump from the bore 30 of the meter-ing valve 3-2 via a passage 90 and an annulus 9-2 in the housing and via an inlet passage in the rotor shaft having a radially extending portion 94 in continuous registry with the annulus 92, an axially extending portion 95 capped by a set screw 98, and a pair of radiating passages 100, 102 (FIG. 6) which communicate directly with one bore 54 of each of the pairs of diametrically opposed bores. The radiating passages 100, 102 are enlarged adjacent the periphery of the shaft 16 to provide valve seats for one-way ball check valves 104 which are suitably retained within the bores 100, 102 by an overhang of the sleeve 37, thereby permitting fuel to flow in one direction to the plunger operating bores 54.

In operation the rotor is driven by the pump drive shaft 38 and the charge pump plungers 56 are thereby caused to reciprocate in the plunger bores 54 by the cam ring 58. Fuel is delivered under pressure from the transfer pump 26 to the pairs of opposed bores through the one-way check valves 104 with the measure or quantity of the fuel supplied to the bores during the outward or initake stroke of the plungers 56 being controlled in the well-known manner by the adjustable metering valve 32. During the inward or discharge stroke of each pair of opposed plungers 56 the associated check valve 104 is closed to isolate the fuel being pressurized from the fuel in inlet passage 96 and the fuel charge is delivered under pressure through the charge pump outlet passage to the associated distributor passage. Each pair of opposed plungers 56 thereby supplies fuel charges to their respective banks of outlet passages, and inasmuch as the distributor passages 74, 76 extend across the rotor shaft 16 these distributor passages register with the outlet passages 82, 84 twice for each revolution of the pump rotor. The pump is therefore adapted for being driven at less than engine speed with each bank of fuel outlets 82, 84 adapted for connection, as to the banks of cylinders of a V-type engine or to the cylinders of an in-line engine. As a result, the pump wear is greatly reduced, the charge pump capacity is increased, control of the fuel supply by the metering valve 32 is improved, and the pump has reliable usefulness particularly in a high speed engine installation. 7

The timing of the delivery of fuel charges is provided by the contour of the cam 58 with the outlet passages 82, 84 being appropriately located for registry with the distributor passages 74, 76, respectively, during the discharge stroke of the pairs of opposed plungers 56. Inasmuch as a full cycle of the pump is provided during only one-half revolution of the pump rotor greater selectivity of fuel timing is obtainable by appropriate selection of the cam contour. It should, of course, be understood that in the usual installation, the cam contour would be designed so that one pair of opposed plungers 56 would be operating in or awaiting the discharge stroke while the other pair of opposed plungers 56 would be operating in or awaiting their intake stroke, thereby providing substantially continuous and uninterrupted fuel flow in the inlet passage of the charge pump and yet provide a discontinuous and, where desirable, delivery of fuel charges to the associated internal combustion engine at uneven intervals, as for example, when used with the usual V- type engine. Additionally, with the reduced pump rotor speed the stress on the operating parts of the pump is substantially reduced thereby ensuring greater pump reliability and allowing for a more compact and sturdy pump construction.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

I claim:

1. In a fuel injection pump having a housing, a rotor mounted in the housing, a fuel distributor, and a charge pump with a cam ring encircling the rotor, plungers reciprocably mounted in radial bores in the rotor for actuation by the cam ring, and fuel inlet and outlet passages; the improvement wherein the charge pump comprises a pair of noncommunicating radial bores, pump plungers mounted for reciprocable movement in the bores, and a pair of fuel outlet passages in the rotor in communication respectively with the pair of bores, and wherein the fuel distributor comprises a pair of axially spaced distributor passages in the rotor in communication respectively with the pair of outlet passages and a pair of axially spaced banks of fuel outlets in the housing adapted for registration respectively with said distributor passages.

2. In a fuel injection pump having a housing, a rotor mounted in the housing, a fuel distributor, and a charge pump with a cam ring encircling the rotor, plungers reciprocably mounted in radial bores in the rotor for actuation by the cam ring, and fuel inlet and outlet passages; the improvement wherein the charge pump comprises a pair of noncommunicating angularly spaced bores in the rotor, plungers mounted for reciprocable movement in the bores, a fuel inlet passage in the rotor having an axially extending passage portion and a pair of angularly spaced radially extending passage portions in communication respectively with the one-way check valves in said radially extending passage portions, and a pair of fuel outlet passages in the rotor in communication respectively with the bores, and wherein the fuel distributor comprises axially spaced distributor passages in the rotor in communication respectively with the pair of'fuel outlet passages and a pair of axially spaced banks of fuel outlets in the housing adapted for registration respectively with said distributor passages.

3. In a fuel injection pump having a housing, a rotor mounted in the housing, a fuel distributor, and a charge pump with a cam ring encircling the rotor, plungers reciprocahly mounted in radial bores in the rotor for actuation by the cam ring, and fuel inlet and outlet passages; the improvement wherein the charge pump comprises four radial bores in the rotor angularly spaced to provide two pairs of diametrically opposed bores, pump plungers mounted for reciprocable movement in the bores, a fuel inlet passage in the rotor having an axially extending passage portion and a pair of angularly spaced radially extending passage portions in communication re spectively with-at least one bore of each pair of opposed bores, one-way check valves in said radially extending passage portions, and a pair of fuel outlet passages in the rotor having nonintersecting radially extending passage portions in communication respectively with the pairs of opposed bores, and axially extending passage portions, and wherein-the fuel distributor comprises axially spaced radially extending distributor passages in the rotor in communication respectively with said axially extending passage portions of the fuel outlet passages and a pair of axially spaced banks of fuel outlets in the housing adapted respectively for registration with said distributor passages.

4. The improvement of claim 3 wherein the distributor passages extend across the rotor whereby each distributor passage registers twice with its respective bank of fuel outlets for each revolution of the rotor.

5. The improvement of claim 3 wherein the rotor comprises a shaft and a sleeve fixed to the shaft and wherein the bores are provided in the sleeve.

6. The improvement of claim 5 wherein the radially extending passage portions of the fuel inlet passage have enlarged passage portions adjacent the periphery of the rotor shaft and the check valves comprise balls received within said enlarged passage portions and retained therein by the sleeve.

7. In a fuel injection pump having a housing, a rotor mounted in the housing, a fuel distributor, and a charge pump with a cam ring encircling the rotor, plungers reciprocably mounted in radial bores in the rotor for actuation by the cam ring, and fuel inlet and outlet passages; the improvement wherein the charge pump comprises a pair of noncommunicaitng radial bores, pump plungers mounted for reciprocable movement in the bores, and a pair of fuel outlet passages in the rotor in communication respectively with the pair of bores, and wherein the fuel distributor comprises a pair of noncommunicating distributor passages in the rotor in communication respectively with the pair of outlet passages and a pair of banks of fuel outlets in the housing adapted for registration respectively with said distributor passages.

8. In a fuel injection pump having a housing, a rotor mounted in the housing, a fuel distributor, and a charge pump with a cam ring encircling the rotor, plungers reciprocably mounted in radial bores in the rotor for actuation by the cam ring, and fuel inlet and outlet passage means; the improvement wherein the charge pump comprises two angularly displaced pairs of diametrically opposed noncommunicating radial bores in the rotor, plungers mounted for reciprocable movement in the bores, a fuel inlet passage in the rotor in communication with the pairs of opposed bores, valve means to isolate selectively and alternatively the fuel inlet passage means from each of said pairs of opposed radial bores, and fuel outlet passage means in the rotor in communication with the pairs of opposed bores, and wherein the fuel distributor comprises a plurality of fuel outlets in the housing selectively and sequentially in communication With the pairs of opposed bores through the fuel outlet passage means.

4/1954 Humber l03-2.l 10/1962 Roosa 1032.1

SAMUEL LEVINE, Primary Examiner.

LAURENCE V. EFNER, Examiner. 

1. IN A FUEL INJECTION PUMP HAVING A HOUSING, A ROTOR MOUNTED IN THE HOUSING, A FUEL DISTRIBUTOR, AND A CHARGE PUMP WITH A CAM RING ENCIRCLING THE ROTOR, PLUNGERS RECIPROCABLY MOUNTED IN RADIAL BORES IN THE ROTOR FOR ACTUATION BY THE CAM RING, AND FUEL INLET AND OUTLET PASSAGES; THE IMPROVEMENT WHEREIN THE CHARGE PUMP COMPRISES A PAIR OF NONCOMMUNICATING RADIAL BORES, PUMP PLUNGERS MOUNTED FOR RECIPROCABLE MOVEMENT IN THE BORES, AND A PAIR OF FUEL OUTLET PASSAGES IN THE ROTOR IN COMMUNICATION RESPECTIVELY WITH THE PAIR OF BORES, AND WHEREIN THE FUEL DISTRIBUTOR COMPRISES A PAIR OF AXIALLY SPACED DISTRIBUTOR PASSAGES IN THE ROTOR IN COMMUNICATION RESPECTIVELY WITH THE PAIR OF OUTLET PASSAGES AND A PAIR OF AXIALLY SPACED BANKS OF FUEL OUTLETS IN THE HOUSING ADAPTED FOR REGISTRATION RESPECTIVELY WITH SAID DISTRIBUTOR PASSAGES. 